1. Field of the Invention
The present invention relates to a resin-sealed semiconductor device in which a semiconductor element such as a flip-chip mounted on a hybrid substrate is sealed with a resin.
2. Description of Related Art
A conventional semiconductor chip is sealed with silicone gel or the like to insulate electrically and to protect the chip from environmental hazards such as water. A hybrid IC (Integrated Circuit) including, a flip-chip, for example, is electrically and mechanically connected with a conductor pattern formed on a thick layer circuit board through soldering bumps formed on a main surface of the flip-chip. The board is packed or sealed with silicone gel.
The silicone gel entering a space between the flip-chip and the board is thermally expanded and pushes up the flip-chip. U.S. Pat. No. 4,812,897 (corresponding to Japanese unexamined patent publication No. Showa 62-149157) suggests to soften the silicone gel in order to reduce the force pushing up the chip and to prevent breakage of the soldering bumps. Therefore, a silicone gel which has a low cross linking density has needed to be used.
A sealing resin needs to be filled with a filler which has a high thermal conductivity in order to reduce a generation of heat by the chip. However, since the silicone gel needs to be hardened in this case, it finally breaks the soldering bumps.